Updated: Sep 26, 2021
There are many causes of dementia, however two specific Neurosurgical conditions are reversible with surgical intervention. In the first of this series, we look at the condition called Normal Pressure Hydrocephalus (NPH).
Although not very common, NPH is a reversible cause of dementia. The classical clinical presentation for NPH is the triad of symptoms: dementia, gait ataxia (difficulty walking and mobilising), and urinary incontinence. Sometimes patients only exhibit some of these symptoms and not necessarily all three. If your doctor suspects NPH, he or she will arrange a CT or MRI brain scan (pictured top left), which may demonstrate dilated cerebral ventricles or ‘hydrocephalus’ which literally translates to “water on the brain”. The cerebral ventricles are normal fluid filled anatomical structures, but in patients with hydrocephalus these ventricles become dilated and an abnormal amount of fluid accumulates in the brain. In patients with NPH, there is fluid accumulation but no increase in the brain pressure, hence the name ‘Normal Pressure Hydrocephalus’.
If you have been diagnosed with NPH you will be referred to see a Neurosurgeon. The diagnosis can be confirmed after taking a medical history, performing a neurological examination, and sometimes further tests like a lumbar puncture ‘tap test’. The purpose of a tap test it to look for any clinical improvement following removal of some of the spinal fluid, and this can be performed at St Andrew's Hospital. The treatment for NPH is insertion of a ventriculoperitoneal shunt (pictured top right), which is a special rubber tube that drains the brain fluid via a unidirectional valve into the peritoneal cavity where the bowel and abdominal contents live, and where the excess fluid can be safely absorbed. In many patients this reverses all the symptoms of NPH, not only the dementia.
If you think you or a family member may have NPH please ask your GP to request a CT brain scan and a referral to see a Neurosurgeon to discuss management options.